Is it all those lattes? Is it something hard-wired in mothers? Maybe it's just a "Look! I'm on top of this mothering thing, so don't mess with me."

I'd like to ask the babies their opinions on the matter. When I see a mother and baby bouncing at a rate of two bounces per second, it's hard to tell whether either is benefiting. Neither looks particularly happy. The crying turns staccato as if someone's pounding on the baby's back, and Mom usually has that nonchalant but stern look of I-don't-want-to-appear-as- stressed-as-I-really-am.

Much of what I observe seems more akin to milkshake making than baby bouncing. Some mothers even look as if they are mixing a martini, with the kid held high, its head bobbing.

Saddest, though, is when Dad does the bouncing, and the baby's face is all, "Could someone h-help m-me, please!"

Let's hope the epidemic of baby bouncing doesn't get linked to the lattes. That could be a large class action suit.

Where's the hard evidence for baby bouncing? If the endpoint is lulling the child to sleep or into a state of calm, there doesn't appear to be any evidence, that I could find.

On the other hand, it took me only 0.09 seconds on Google to come up with more than a million hits on fussy babies. And, in fairness, although none that I scanned recommended bouncing per se, many of the suggestions do involve rhythmic motion of some kind.

Bouncing is not one of 36 time-tested baby calmers listed on Dr. Sears' excellent website (www.askdrsears.com). Some of the preferred methods are rocking, dancing, driving in the car and jumping on a trampoline. (Try that at 2 o'clock in the morning!)

Surprisingly, the concept of no motion gets very little play anywhere. Just holding a crying baby, or placing the baby in a comfortable bed/crib/bassinette until it drifts off, are never mentioned. Anecdotally, it's precisely this "no motion" concept (i.e. holding, lovingly) that worked best for our three kids, and, so far, they're not too psychologically damaged. Wearing the baby in a sling, listed at the top of Sears' 36 baby-calmers, was the closest to "holding" I saw.

There is some evidence to support picking up crying babies, as opposed to letting them cry it out. Early work favored the latter, but Sears points out that those who preached this were nearly always male. It took women getting into the field to set things straight. He refers to research by Sylvia Bell and Mary Ainsworth in the 1970s that showed less demanding behavior and crying at 1 year of age in babies whose mothers responded promptly to their crying, compared with babies in the cry-it-out group.

When all the evidence is in, it may turn out that the Beatles had it right: All you need is love, and beyond that, nuances matter little. Concerning the bouncing in public: To each, her own, but maybe slow it down a bit? As humanity strives for perfection in child rearing, I like to keep in mind the tongue-in-cheek quotation from Canadian writer Robertson Davies: "A happy childhood has spoiled many a promising life."

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Dr. James Channing Shaw is a dermatologist at the University of Toronto.